Description of the Prior Art
A major objective of present day data processing technology is to reduce the size and cost of systems while increasing data handling capability and reliability. Data processors or computers typically include one or more disk drives. A laptop computer which needs to be portable, and therefore compact and light in weight, generally has a single compact disk drive which comprises, inter alia, at least one magnetic disk, a drive motor, magnetic heads and a head actuator. The head actuator generally is a voice coil motor that rotates the heads to selected data tracks on the surface of the storage disk. In prior art disk drive assemblies, the form factors allowed ample length so that the voice coil motor could be large enough to meet the desired performance specifications, especially average access time. The length of the disk drive assembly is thus driven by the need for space for the voice coil motor. The voice coil motor of the head actuator uses a magnet housing which occupies substantial space in prior art disk drives. Also prior art construction employs separate components for the magnetic yoke which is susceptible to resonant vibrations at the mating surfaces. In the event of failure of the head actuator, the actuator components need to be removed and replaced separately which is time-consuming.
With the development of laptop and notebook portable computers, disk drive designs have been modified and thus deviate from conventional designs that have standard form factors. The departure from standard form factors has allowed reduction in size and weight of the disk drive. Nevertheless further reduction in size and weight is still desirable to realize the use of minimal space in a laptop or notebook computer.
Conventionally magnetic disks are made with highly polished aluminum substrates on which a thin magnetic layer is deposited. Aluminum substrates are subject to damage due to head crashes which may occur when the heads are track seeking across the surface of the disk. It is desirable to use a material for a disk substrate that provides better performance and reliability, and allows the heads to fly closer to the disk surfaces so that data density can be increased.
Known prior art disk drives generally assemble the magnetic disk to the drive motor by means of bolts or screws. This type of assembly is time consuming and requires proper alignment and is subject to tight mechanical tolerances. With the use of bolts or screws, removal and replacement of a damaged disk involves intensive labor cost and unduly long down time.